Safety-shield for gas-mains



(No Model.)

B. HEBER.

SAFETY SHIELD FORYGAS MAINS. v 7 No. 316,967. Patented May 5, 1885.

n. PETERS Plmn-ulhognpher. Washington. 0. c,

UNITED STATES ROBERT HEBER, OF TITUSVILLE, PENNSYLVANIA.

SAFETY-SHIELD FOR GAS-MAINS.

SPECIFICATION forming part of Letters Patent No. 316,967, dated May 5,1885.

Application filed February 10, 1885. (No model.)

To all whom it may concern.-

Be it known that 1, ROBERT HEBER, a citizen of the United States,residing at Titusville, in the county of Crawford and State ofPennsylvania, have invented an Improvement in Safety-Shields forGas-Mains, of which the following is specification.

My invention relates to an outside shield or safety-pipe for pipesconveying gas, steam, or fluid under pressure; but more especially pipesor mains for conveying natural gas where the pressure is very great, andwhere the escaping gas permeates the soil, and from thence into thesewers or buildings adjacent thereto, and, mingling with the atmosphere,forms a dangerous explosive compound, my object being to construct anoutside pipe inclosing the main, which shall retain the fluid escapingfrom any leak in the main, and in which the fluid can be retained orconveyed by an escape-pipe to a safe point of discharge, and to soconstruct the outer pipe that it can be entered at any point and themain repaired; also, to. separate the space between the main pipe andthe shield into separate chambers, each chamber having an escape-pipe,so that escaping gas cannot travel a long distance inside the shield,and the location of the leak be determined by examination of theescape-pipes. This I accomplish by the device illustrated in theaccompanying drawings, in which- Figure 1 is an outside view of onesection and a portion of an adjoining section of my shield as laid,inclosing the main and showing the escape-pipe; Fig. 2, across-sectionof Fig. 1 on line 00 m,- Fig. 3, a view of the main,with the outer halfof the shield removed,on line y y, Fig. 2, and showing the packing.device for dividing the air-space into chambers; Fig. 4, a similarsection, showing the main and with the shield broken,on line 2 2:, Fig.2, and showing the stem of a throttle-valve in the main projectingthrough the shield; Fig. 5, a section of elbow-joint inclosing an elbowin the main; and Fig. 6, an enlarged cross-section of the main andshield, showing more clearly the cradle for supporting the main.

Similar letters in the several views refer to similar parts.

A is the gas-main, put together in the ordinary manner; 13, the shieldor inclosing-pipe.

This is constructed in sections and united,wheu laid,by flanges andbolts to the adjoining section. Each section is also dividedlongitudinally into half-cylinders, each half having the flange C oneach edge, by which and with the aid of bolts it is joined with theother half, so that the two pieces maybe placed around the main and thenbolted together.

D is the end flange of the section for joining it to the adjoiningsection.

It is now evident that the whole main pipe may be inclosed by thesehalf-cylinders, and that when properly put together, the joints packedwith lead or any suitable packing and bolted, that a tight and strongpipe is formed inclosing the main and leaving an air-space between thetwo pipes. Whenever it becomes necessary to have access to the mainpipe, it may be done by removing the bolts from any one half-section,when it can be removed and replaced at pleasure.

For the purpose of dividing the air-space between the two pipes intoseparate chambers, and preventing the flow of gas escaping from the mainpipe along the main pipe for any considerable distance, packing-j ointsmay be constructed, as often as may be desired, in the manner shown at Pin Fig. 3. A shoulder or ring, E, being constructed on the inside of onesection, and a follower, F, filling the space between the main pipe andshield being attached to and projecting from the adjoining section, thespace G around the main and in front of the ring E being filled withhemp or other packin g, the follower F is inserted, and the sections,

being drawn together, compress the packing and form a tight joint aroundthe main, preventing the passage of any gas along the outside of themain. From each separate chamber so made is at least one escape-pipe, H,through which the gas (or other fluid) escaping from the main isconducted away to some safe point for burning or escaping into theatmosphere. Each chamber having its separate escape-pipe, the locationof any leak in the main can be detected by examining the escape-pipesalong the line.

For supporting the main inside the shield, at suitable distances isplacedthe cradle I, (shown more clearly in Fig. 6,) the cradle beingmade to fit the lower part of the shield and rising and supporting themain at the sides and below the center. Under the main is placed theroller K, on which the main rests, and which, while supporting the main,allows to it a free motion longitudinally with the pipes.

Where it is necessary to place a valve in the main pipe, the shieldmaybe cut and stopped on each side of the throttle or valve; or onehalf-section may be made as shown in Fig. 4, the shield being enlargedsufficiently to inclose the valve, and the valve-stem be packed with anordinary stuffing box where it passes through the shield.

I make no claim to the device of a larger pipe with escapes therefrominclosing the main as a means of controlling the escaping fluid, whensuch larger pipe is made and put down in the ordinary manner, thatdevice having been used before.

What I do claim as my invention is 1. An inclosing-shield for agas-main, con sisting of a larger pipe inclosing the main, of sufficientstrength to withstand the pressure of gas in the main,ifnecessary,andwith the upper part of the shield constructed in sections, any one ofwhich may be removed at pleasure without disturbing the adjoiningsections, thereby securing access to the main at any point, the spacebetween the main and the shield being divided into separate consecutivechambers by packing-rings constructed at proper distances between theoutside of the main pipe and the shield, so that any gas leaking orescaping from the main cannot flow along the main from one chamber tothe next, and with a free escapepipe from each chamber for conveying anygas escaping from the main to a safe point for mingling with theatmosphere, the chambers being contiguous and the shield continuous, thewhole main pipe adequately protected, sub stantially as shown anddescribed.

2. In asafety-shield, a pipe inclosing a main pipe used for conveyingnatural gas, as a device for separatingthe space between the main pipeand shield into chambers, a packing-boX consisting of a ring on theinside of one joint of the shield near one end and a follower on theadjacent end of the next joint, the space between the ring and thefollower being filled with hemp or other packing, which is compressed bythe drawing together of the two joints either by flange union withbolts,or by screwing one joint of pipe into the other, substantially asdescribed.

ROBERT HEBER.

Witnesses:

G. W. VVEAVER, JOHN ONEILL.

